This 5 milliwatt violet laser emits light with a wavelength of 405 nanometers, almost in the ultraviolet.
It is great for making fluorescent objects glow. It is the same laser we use to write messages on our Kryptonite sheets
You can write on them from across the room if you have a very steady hand.
We use them on hikes to illuminate fluorescent rocks, fungi and scorpions from a safe distance.
Requires 2 AAA batteries (not included).